1. Technical Field
The present disclosure relates to an electronic circuit. More particularly, the present invention relates to a driving circuit and an error amplifier thereof.
2. Description of Related Art
Light emitting diodes (LEDs) are in estimation four times as efficient as conventional incandescent lights. The LEDs are also considered to be more economically sound than compact fluorescent bulbs that contain environmentally harmful mercury required further processing, and are supposed to last longer than that the conventional lighting does. In this regard, the LEDs have been becoming the mainstream of the lighting technology.
A driving circuit for driving the LEDs includes an error amplifier for comparing a reference voltage with a feedback voltage to charge a compensation capacitor with an error current. The charge speed of the compensation capacitor corresponds to both the capacitance of the compensation capacitor and the magnitude of the error current. Generally, a high error current is required to charge the compensation capacitor quickly during a start-up period. However, such high error current may induce the oscillation of the driving circuit while the driving circuit is activated and in operation. Therefore, the compensation capacitor with a high capacitance, which undesirablly blocks the charge speed of the compensation capacitor, is still needed to keep the driving circuit from the oscillation.
Given the above, the dilemma of choosing between the capacitance of the compensation capacitor and the magnitude of the error current should be solved.